1. Field of the Invention
The invention relates to the treatment of di-aryl monochlorophosphine waste residue and in particular to a method of treating the diphenylphosphinous chloride-aluminum chloride residue complexes derived from the manufacture of diphenylphosphinous chloride.
2. Related Art
Diphenylphosphinous chloride is a reaction derivative used as an intermediate for the production of U. V. stabilizers, polymerization catalysts and specialty products. A process for producing diphenylphosphinous chloride is by the Friedel-Crafts autogenous reaction of diphenyl dichlorophosphine in the presence of aluminum chloride. The reaction, in addition to producing phenyl dichlorophosphine, also produces a residue and phosphorus trichloride.
The residue obtained from this reaction is comprised of a complex having the formula AlCl.sub.3.2(C.sub.6 H.sub.5).sub.2 PCl. The residue which reacts with water to produce HCl is liquid at 100.degree. C. but is solid at ambient temperatures. The amount of residue generated in the process is dependent on the proportion of the catalyst used.
At the present time the residue is disposed of in drums in approved land-fill sites. Land-fill disposal of chemical waste has become increasingly controversial and alternative methods of safe waste disposal have been sought.
An object of the present invention is to develop an alternative means for disposing of waste material derived from the production of diphenylphosphinous chloride. A further object of the invention is to remove the aluminum metal from the residue so that the residue can safely be incinerated. Removal of the aluminum content of the residue is desirable to avoid damage to the refractory lining of the incinerator.